Maybe the WildTrail WT3M (triple) or WT1M (single). 21700 cell so it has a larger diameter which is more comfortable to grasp while pressing a button for hands that may be weaker or arthritic, and the side switch on this one is very easy to press and in a natural position. It’s compact but still has a traditional look to it, which she’s probably used to. Runs anduril so you can muggle it for her and set the ceiling lower if you like, and she can enjoy the ease of the ramping or stepped light settings. Switch backlight can be off or set at different levels. It has USB-C charging, so no fumbling or damaging the cable or port trying to find the right side of a micro-usb. The only quibble might be that the rubber port cover is a tight fit and not the easiest to pop open, but it’s easily removed or she could use a fork tine or whatever to pop it out. I don’t think a protected cell will fit in there but with a 21700 and low level use it should last way longer than a couple weeks even with the switch light set to high. The wider head will make it easier for her to set it on a countertop or whatever without tipping over so easily, but this one will roll easily if laid on its side.
Another idea is the Wurkkos FC11, single emitter 18650. It uses the simple UI like many Sofirn lights where you can choose ramping or stepped, but it’s not so feature-laden or potentially confusing like anduril. They have a smaller diameter of course, a bit more length, and an easy to press side switch. Also USB-C and the cover is easy to pop open but stays put in use.
I’d probably vote for the WildTrail unless her hands prefer longer/thinner of the 18650 tube lights. Since she grew up with dim halogen lights, maybe ask her if she likes that warmer color temp more than neutral white or ugly-cold-blue white of the cheapie flashlights and pick the emitter accordingly.